Tag: importance of light for photosynthesis

Questions Related to importance of light for photosynthesis

Word dark reaction for biosynthetic phase of photosynthesis is misnomer word because ___________________.

biology photosynthesis and respiration experiments on photosynthesis - light importance of light for photosynthesis photosynthesis necessities- experiments

  1. Dark reaction occur during dark

  2. Dark reaction occur during day

  3. Dark reaction is completely free from light

  4. Dark reaction occur during short dark intervals

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Correct Option: A

The chemical compound used in the experiment to show that oxygen is evolved during photosynthesis is

botany plant nutrition experiments on photosynthesis - light importance of light for photosynthesis photosynthesis necessities- experiments various experiments on photosynthesis experiments on photosynthesis - gases

  1. KOH.

  2. NaOH.

  3. KHCO$ _{3}$.

  4. All of the above.

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Correct Option: C

In 1772, Joseph Priestley demonstrated that

botany how plants grow experiments on photosynthesis - light importance of light for photosynthesis photosynthesis necessities- experiments various experiments on photosynthesis experiments on photosynthesis - gases

  1. Plants foul the air

  2. Animals purify the air during day time

  3. Plants and animals restore air for each other

  4. Plants get killed in the air produced by animals

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Correct Option: C
Explanation:
Joseph Priestley discovered oxygen which is used by the plant and animals. He demonstrated that plants liberate oxygen as a product during photosynthesis and that oxygen is utilised by the animals during respiration. Further, plant consumes the carbon dioxide, exhaled by the animals, to carry out photosynthesis. Thus plants and animals restore air for each other.
So the correct answer is 'Plants and animals restore air for each other'.

A green plant bends towards the source of light when exposed to the light on only one side, it bends towards the source of light as it grows. Which of the following is the best explanation of the phenomenon 

biology photosynthesis and respiration experiments on photosynthesis - light importance of light for photosynthesis photosynthesis necessities- experiments

  1. The apices of their stems are attracted by light

  2. They need light for photosynthesis

  3. Some auxins accumulates on the shaded side to induce greater cell elongation on that side

  4. Light stimulates the cells on the illuminated side to increase in length

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Correct Option: C
Explanation:

Accumulation of auxin as the apex of the plant, which is responsible for the phototropism movement so that plant cells are elongated.

So the correct option is C.

Hydrilla leaf is used in an experiment to test that

botany how plants grow experiments on photosynthesis - light importance of light for photosynthesis photosynthesis necessities- experiments various experiments on photosynthesis experiments on photosynthesis - gases

  1. Chlorophyll is necessary for photosynthesis.

  2. Light is necessary for photosynthesis.

  3. CO$ _{2}$ is necessary for photosynthesis.

  4. Oxygen is evolved during photosynthesis.

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Correct Option: D
Explanation:

To test that oxygen is evolved during photosynthesis few fresh Hydrilla plants in a glass beaker filled with water. A pinch of KHCO$ _{3}$ is added to it. It is kept in sunlight. After some time some bubbles (oxygen) escapes from the plant. This proves that oxygen is produced during the photosynthesis. It is evolved during the light reaction of the photosynthesis.

So, the correct answer is option D.

Green plants, normally do not suffer from the deficiency of

botany how plants grow experiments on photosynthesis - light importance of light for photosynthesis photosynthesis necessities- experiments various experiments on photosynthesis experiments on photosynthesis - gases

  1. Phosphorus

  2. Sulphur

  3. Iron

  4. Carbon

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Correct Option: A

Two green plants are kept separately in oxygen free containers, one in the dark and the other in continuous light. Which one will live longer? 

biology photosynthesis and respiration experiments on photosynthesis - light importance of light for photosynthesis photosynthesis necessities- experiments

  1. The plant kept in dark

  2. The plant kept in light

  3. Both the plants will live for the same time

  4. None of the above

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Correct Option: B
Explanation:

The plant kept in continuous light will live longer, because it will be able to produce oxygen required for its respiration by the process of photosynthesis.

Oxygen is evolved as a by-product of photosynthesis during photolysis of water.
So, the correct answer is option B.

(i) Pluck the leaf to be experimented
(ii) Cover a portion of leaf on both sides by using strips of black paper
(iii) Keep the plant in dark place for three days to destarch its leaves.
(iv) Test the experimental leaf the the presence of starch 
(v) Expose the plant to sunlight for four hours 
(vi) Remove the black paper strip from the leaf

Given in the box are steps written randomly for the experiment to show that light is essential for photosynthesis. Which of the following sequences of steps is to be followed by the successful run of the experiment?

biology photosynthesis and respiration experiments on photosynthesis - light importance of light for photosynthesis photosynthesis necessities- experiments

  1. (i), (iii), (ii) (iv), (v), (vi)

  2. (ii), (i), (v), (vi), (iii), (iv)

  3. (iii), (ii), (v), (i), (vi), (iv)

  4. (v), (ii), (i), (iii), (iv), (vi)

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Correct Option: C
Explanation:

The starch in the leaves is eliminated by keeping the plant in a dark place for 3 days. A leaf is selected and covered with a black strip on both sides. The plant is kept in sunlight for 4 hours. The experimental leaf is plucked and the strip is removed from it to perform the starch test. It is found that he leaf covered with black paper will turn brown and the part of the exposed leaf will turn blue-black. This result proves that starch is formed in the leaf where sunlight is available and is not formed in absence sunlight. Thus the correct answer is option  C.

UV or X-ray radiation is NOT suitable for photosynthesis is green plants because such a radiation.

biology photosynthesis and respiration experiments on photosynthesis - light importance of light for photosynthesis photosynthesis necessities- experiments

  1. Is not visible

  2. Is not absorbed by chlorophyll

  3. Causes ionization of chlorophyll

  4. Leads to an increase in rotational and vibration energy of chlorophyll

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Correct Option: A

How many molecules of water are needed by a green plant to produce one molecule of hexose reduce $6$ molecules of $CO _{2}$?

botany how plants grow experiments on photosynthesis - light importance of light for photosynthesis photosynthesis necessities- experiments various experiments on photosynthesis experiments on photosynthesis - gases

  1. $6$

  2. $12$

  3. $24$

  4. Only one

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Correct Option: A